Keilbasa should be eaten with cabbage and horse radish. Period, the end.

If that's not your taste, that's cool. It's not for everyone. But that is what Polish sausage SHOULD be eaten with. You can debate what you prefer with it, be it mustard, ketchup, relish, mayo, whatever. But if you're eating kielbasa with anything but a big dollop of horse radish on it, you're doing it wrong.

Also, I go news for you, if it's not made by a Polish family (i.e. if the brand name is less that 18 letters long), it's just a hot dog different spices. And god help you if you get one in Pittsburgh. For reasons unknown, they put brown sugar in it. Just another reason to hate steel city.